p.2

[Left Page]
is therefore one foot too low. -- Please
see whether there has been any change
of this kind, and whether this will
make the results move in accordance with
those at the other stations. If the trouble
is not here I will look farther into
the matter.

Please send me you montly results for
1868 & 1869 - also for November 1871, when
ready.

My annual averages include observations
made in the winter & hence are lower
than yours. You will notice that
I use our zero - always subtracting your
figure from 5.00-

[Right Page]
Table showing the Mean of Lake Michigan
[Milwaukee city lake survey]